1. Field of the Invention
The invention relates to a drive arrangement for shearing drums, in which the final gear reduction stages are arranged inside the shearing drum and at least one reduction stage is designed as a planetary gear mechanism.
2. Description of the Prior Art
Drive arrangements of the type mentioned at the beginning can be taken for example from U.S. Patent Specification 3,773,384. In the case of such known devices, a central drive shaft extends over the entire width of the shearing drum, with which shaft the individual zones of the rotating shearing drum are connected. Usually, shearing drums on drum shearing machines are supported by means of at least two carriers running in the longitudinal direction of the machine and pivotal in the vertical direction and therefore the drive of such shearing drums is usually carried out via two drive shafts, of which one drive shaft drives into rotating movement the region of the shearing drum located between the carriers of the shearing drum and the second drive drives into rotational movement the two lateral zones of the shearing drum. In these cases as well, axial shafts which critically restrict the space available inside the shearing drum are necessary. In particular for the feeding of fluid and the leading-in of control lines, for example for a spraying of picks, with the known designs of drive there usually only remains available as a free hollow space the region of the drums which is away from the axis, as a result of which considerable sealing problems arise. In the case of an actuation for drum widenings as well, which are known in the form of hydraulic actuations, the hydraulic medium cannot be led to the drives of such a drum widening without complex sealing measures.